SEATTLE — A team of Stanford research scientists recently created a cheap and simple solution to improve public health in poor regions: a microchip that can perform multiple diagnostic tests as effectively as expensive lab equipment. The microchip only takes twenty minutes to assemble and costs a penny to make.
Whether because of limited funds, weak public health infrastructure or a lack of electricity, impoverished countries have limited resources when it comes to medical testing. Diagnosing diseases such as HIV and malaria usually requires costly lab tests that hospitals in poor countries cannot afford.
Women in wealthy nations are twice as likely to survive breast cancer — the most commonly occurring cancer in women — than women in low-income countries. Early detection of breast cancer is crucial to the odds of survival but cannot be achieved without expensive lab equipment that performs diagnostic tests. Isolating cells, or cell sorting, is critical to diagnosing common diseases such as malaria, tuberculosis, HIV and cancer. Developing countries need diagnostic tests that are cheap, easy to use and capable of diagnosing a range of diseases.
Stanford research associate Rahim Esfandyarpour and his team recognized the need for a different kind of diagnostic technology to improve public health in poor regions, so they created the “lab-on-a-chip” to simplify the diagnostic process. Researchers have been working toward microchip technology for more than 20 years, but this is the first breakthrough success.
The microchip is a few millimeters to a few centimeters in size and consists of two layers: a silicone layer for holding the fluid sample (blood, saliva or other cells) and a flexible plastic layer with a circuit design that manipulates the cells.
According to Kendra Pierre-Louis from Popular Science, “in other lab-on-a-chip contraptions, the silicone chip is etched with designs. In Esfandyarpour’s version, the chip is left blank,” allowing for reuse. The second layer is printed with a simple inkjet printer. The two layers work together to separate cells in different directions based on their positive or negative charges. In a test for breast cancer, the cancer cells would separate from healthy cells, making for an easy diagnosis. Esfandyarpour’s team ran many tests on the microchip until it was able to trap and isolate cells without killing them.
The microchip does everything sizable, expensive lab equipment can do for a tiny fraction of the price. In the past, similar technologies ran into difficulty because they were not tested and reviewed properly, but this lab-on-a-chip went through extensive tests and peer review. The test results were published in the journal for the Proceedings of the National Academy of Sciences (PNAS) for public viewing.
Technicians using the microchip won’t need to create their own circuit designs because they can print designs on the second layer of the chip using an existing template. Not only are the microchips cheap, but they can also be reused because the chips don’t come into contact with the patient. Esfandyarpour also wanted the chips to have a sustainable impact on public health in poor regions – the chips don’t have to be used strictly for diagnostic purposes, they can also allow for experimenting so that researchers living in poverty can expand their knowledge of the disease and improve the public health infrastructure in their communities.
– Rachel Cooper